As far as tech support, it's not that great. Really noone's is. It's basically someone no more computer knowledgable than an average non-computer professional, who tries to mach up what you say to them to a database they have of common problems and solutions. And if you are not very knowledgeable yourself, then you will likely be using terms they are not familiar with and which might be incorrect which makes it hard for them.
On the other hand, if you are pretty knowledgeable, the only thing that usually goes wrong is hardware failure. And you'll know what it is and can call in and ask for a replacement. This is what I have always done. But in this case you first have to humor them in letting them try to remedy it using their database of magic tricks. But if your persistent the call will end up with them saying "yes, it sounds like your [insert part here] needs to be replaced. And they will send it to you. They may try to tell you that you have to send the notebook in, instead, I tell them I can replace it myself, just send me the part. You have full instructions to replace this part on your customer service website. (And they do.) Next day or 2 you get your part, everything's cool.
The Complete Care is just accident insurance. Sometimes I get it, sometimes I don't. So far in 5 years of Dell purchases, I've never had an accident while I had the Complete Care, but I feel comfortable with the service, as I've never heard any complaints about it. One time I did drop a ceramic plait on my 4150 and it popped out a key and broke the key attachment piece. I called Dell about it and they said they could only replace the whole keyboard, but they never billed me for it, even though I told them it was my fault and that I had dropped a plate on it, and I hadn't bought the Complete Care on this notebook. Complete Care is not bullshit, though, given that they replaced my keyboard without it, I think they would certainly replace things if you had it.
I bought Complete Care with my most recent 9300 and iXPS2 purchases. $100 for 2 years of oops insurance is a great deal on a $2000 to $3000 product, I think, especially for something I move around a lot.